8204947: Port ShenandoahTaskTerminator to mainline and make it default
Reviewed-by: tschatzl, rkennke
/build/
/dist/
/.idea/
nbproject/private/
/webrev
/.src-rev
/.jib/
.DS_Store
.metadata/
.recommenders/
test/nashorn/script/external
test/nashorn/lib
NashornProfile.txt
**/JTreport/**
**/JTwork/**